[PATCH v4] ARM: rpi: parse useful data from vc fdt
Daniel Brát
danek.brat at gmail.com
Fri Jun 17 14:58:11 PDT 2022
Videocore first-stage loader on rpi passes us many useful information
inside the vc fdt, including the real value of PM_RSTS register, not
easily available by other means and which we can use to determine
the reset cause.
Also make the relevant funtions just print error/warning and continue
in case of some errors, since the fdt from vc is now optional for
barebox's basic function.
Signed-off-by: Daniel Brát <danek.brat at gmail.com>
---
arch/arm/boards/raspberry-pi/rpi-common.c | 183 +++++++++++++++++-----
drivers/watchdog/bcm2835_wdt.c | 23 +--
include/soc/bcm283x/wdt.h | 40 +++++
3 files changed, 182 insertions(+), 64 deletions(-)
create mode 100644 include/soc/bcm283x/wdt.h
diff --git a/arch/arm/boards/raspberry-pi/rpi-common.c b/arch/arm/boards/raspberry-pi/rpi-common.c
index 12a4f4a0a..eaca4edef 100644
--- a/arch/arm/boards/raspberry-pi/rpi-common.c
+++ b/arch/arm/boards/raspberry-pi/rpi-common.c
@@ -23,13 +23,28 @@
#include <linux/sizes.h>
#include <globalvar.h>
#include <asm/system_info.h>
+#include <reset_source.h>
#include <mach/core.h>
#include <mach/mbox.h>
#include <mach/platform.h>
+#include <soc/bcm283x/wdt.h>
+
#include "lowlevel.h"
+//https://www.raspberrypi.com/documentation/computers/raspberry-pi.html#BOOT_ORDER
+static const char * const boot_mode_names[] = {
+ [0x0] = "unknown",
+ [0x1] = "sd",
+ [0x2] = "net",
+ [0x3] = "rpiboot",
+ [0x4] = "usbmsd",
+ [0x5] = "usbc",
+ [0x6] = "nvme",
+ [0x7] = "http",
+};
+
struct rpi_priv;
struct rpi_machine_data {
int (*init)(struct rpi_priv *priv);
@@ -186,54 +201,131 @@ static int rpi_env_init(void)
return 0;
}
-/* Extract /chosen/bootargs from the VideoCore FDT into vc.bootargs
- * global variable. */
-static int rpi_vc_fdt_bootargs(void *fdt)
+/* Some string properties in fdt passed to us from vc may be
+ * malformed by not being null terminated. In that case, create and
+ * return a null terminated copy.
+ */
+static char *of_read_vc_string(struct device_node *node,
+ const char *prop_name,
+ bool *is_dyn)
+{
+ int len;
+ char *str;
+
+ str = (char *)of_get_property(node, prop_name, &len);
+ if (!str || len <= 0)
+ return NULL;
+ if (is_dyn)
+ *is_dyn = str[len - 1] != '\0';
+ return str[len - 1] == '\0' ? str : xstrndup(str, len);
+}
+
+static u32 rpi_boot_mode, rpi_boot_part;
+/* Extract useful information from the VideoCore FDT we got.
+ * Some parameters are defined here:
+ * https://www.raspberrypi.com/documentation/computers/configuration.html#part4
+ */
+static void rpi_vc_fdt_parse(void *fdt)
{
- int ret = 0;
- struct device_node *root = NULL, *node;
- const char *cmdline;
+ int ret;
+ struct device_node *root, *chosen, *bootloader;
+ enum reset_src_type rst_src = RESET_UKWN;
+ char *str;
+ bool is_dyn;
+ u32 pm_rsts;
root = of_unflatten_dtb(fdt, INT_MAX);
- if (IS_ERR(root)) {
- ret = PTR_ERR(root);
- root = NULL;
- goto out;
+ if (IS_ERR(root))
+ return;
+
+ str = of_read_vc_string(root, "serial-number", &is_dyn);
+ if (str) {
+ barebox_set_serial_number(str);
+ if (is_dyn)
+ free(str);
+ } else {
+ pr_warn("no 'serial-number' property found in vc fdt root\n");
}
- node = of_find_node_by_path_from(root, "/chosen");
- if (!node) {
- pr_err("no /chosen node\n");
- ret = -ENOENT;
- goto out;
+ str = of_read_vc_string(root, "model", &is_dyn);
+ if (str) {
+ barebox_set_model(str);
+ if (is_dyn)
+ free(str);
+ } else {
+ pr_warn("no 'model' property found in vc fdt root\n");
}
- cmdline = of_get_property(node, "bootargs", NULL);
- if (!cmdline) {
- pr_err("no bootargs property in the /chosen node\n");
- ret = -ENOENT;
+ chosen = of_find_node_by_path_from(root, "/chosen");
+ if (!chosen) {
+ pr_err("no '/chosen' node found in vc fdt\n");
goto out;
}
- globalvar_add_simple("vc.bootargs", cmdline);
+ bootloader = of_find_node_by_name(chosen, "bootloader");
+
+ str = of_read_vc_string(chosen, "bootargs", NULL);
+ if (str)
+ globalvar_add_simple("vc.bootargs", str);
+ else
+ pr_warn("no 'bootargs' property found in vc fdt '/chosen'\n");
+
+ str = of_read_vc_string(chosen, "overlay_prefix", NULL);
+ if (str)
+ globalvar_add_simple("vc.overlay_prefix", str);
+ else
+ pr_warn("no 'overlay_prefix' property found in vc fdt '/chosen'\n");
+
+ str = of_read_vc_string(chosen, "os_prefix", NULL);
+ if (str)
+ globalvar_add_simple("vc.os_prefix", str);
+ else
+ pr_warn("no 'os_prefix' property found in vc fdt '/chosen'\n");
+
+ ret = of_property_read_u32(chosen, "boot-mode", &rpi_boot_mode);
+ if (ret && bootloader)
+ ret = of_property_read_u32(bootloader, "boot-mode", &rpi_boot_mode);
+ if (ret)
+ pr_debug("'boot-mode' property not found in vc fdt\n");
+ else
+ globalvar_add_simple_enum("vc.boot_mode", &rpi_boot_mode,
+ boot_mode_names,
+ ARRAY_SIZE(boot_mode_names));
+
+ ret = of_property_read_u32(chosen, "partition", &rpi_boot_part);
+ if (ret && bootloader)
+ ret = of_property_read_u32(bootloader, "partition", &rpi_boot_part);
+ if (ret)
+ pr_debug("'partition' property not found in vc fdt\n");
+ else
+ globalvar_add_simple_int("vc.boot_partition", &rpi_boot_part, "%u");
- switch(cpu_architecture()) {
- case CPU_ARCH_ARMv6:
- globalvar_add_simple("vc.kernel", "kernel.img");
- break;
- case CPU_ARCH_ARMv7:
- globalvar_add_simple("vc.kernel", "kernel7.img");
- break;
- case CPU_ARCH_ARMv8:
- globalvar_add_simple("vc.kernel", "kernel8.img");
- break;
- }
+ if (IS_ENABLED(CONFIG_RESET_SOURCE)) {
+ ret = of_property_read_u32(chosen, "pm_rsts", &pm_rsts);
+ if (ret && bootloader)
+ ret = of_property_read_u32(bootloader, "rsts", &pm_rsts);
+ if (ret) {
+ pr_warn("pm_rsts could not be get from vc fdt\n");
+ } else {
+/*
+ * https://github.com/raspberrypi/linux/issues/932#issuecomment-93989581
+ */
+ if (pm_rsts & PM_RSTS_HADPOR_SET)
+ rst_src = RESET_POR;
+ else if (pm_rsts & PM_RSTS_HADDR_SET)
+ rst_src = RESET_JTAG;
+ else if (pm_rsts & PM_RSTS_HADWR_SET)
+ rst_src = RESET_WDG;
+ else if (pm_rsts & PM_RSTS_HADSR_SET)
+ rst_src = RESET_RST;
+ reset_source_set(rst_src);
+ }
+ }
out:
if (root)
of_delete_node(root);
-
- return ret;
+ return;
}
static void rpi_vc_fdt(void)
@@ -241,7 +333,6 @@ static void rpi_vc_fdt(void)
void *saved_vc_fdt;
struct fdt_header *oftree;
unsigned long magic, size;
- int ret;
/* VideoCore FDT was copied in PBL just above Barebox memory */
saved_vc_fdt = (void *)(arm_mem_endmem_get());
@@ -260,16 +351,23 @@ static void rpi_vc_fdt(void)
return;
size = be32_to_cpu(oftree->totalsize);
- if (write_file("/vc.dtb", saved_vc_fdt, size)) {
+ if (write_file("/vc.dtb", saved_vc_fdt, size))
pr_err("failed to save videocore fdt to a file\n");
- return;
- }
- ret = rpi_vc_fdt_bootargs(saved_vc_fdt);
- if (ret) {
- pr_err("failed to extract bootargs from videocore fdt: %d\n",
- ret);
- return;
+ rpi_vc_fdt_parse(saved_vc_fdt);
+}
+
+static void rpi_set_kernel_name(void) {
+ switch(cpu_architecture()) {
+ case CPU_ARCH_ARMv6:
+ globalvar_add_simple("vc.kernel", "kernel.img");
+ break;
+ case CPU_ARCH_ARMv7:
+ globalvar_add_simple("vc.kernel", "kernel7.img");
+ break;
+ case CPU_ARCH_ARMv8:
+ globalvar_add_simple("vc.kernel", "kernel8.img");
+ break;
}
}
@@ -348,6 +446,7 @@ static int rpi_devices_probe(struct device_d *dev)
armlinux_set_architecture(MACH_TYPE_BCM2708);
rpi_env_init();
rpi_vc_fdt();
+ rpi_set_kernel_name();
if (dcfg && dcfg->init)
dcfg->init(priv);
diff --git a/drivers/watchdog/bcm2835_wdt.c b/drivers/watchdog/bcm2835_wdt.c
index ece80837b..c6e6a289f 100644
--- a/drivers/watchdog/bcm2835_wdt.c
+++ b/drivers/watchdog/bcm2835_wdt.c
@@ -10,28 +10,7 @@
#include <restart.h>
#include <watchdog.h>
-#define PM_RSTC 0x1c
-#define PM_RSTS 0x20
-#define PM_WDOG 0x24
-
-#define PM_WDOG_RESET 0000000000
-#define PM_PASSWORD 0x5a000000
-#define PM_WDOG_TIME_SET 0x000fffff
-#define PM_RSTC_WRCFG_CLR 0xffffffcf
-#define PM_RSTC_WRCFG_SET 0x00000030
-#define PM_RSTC_WRCFG_FULL_RESET 0x00000020
-#define PM_RSTC_RESET 0x00000102
-
-#define PM_RSTS_HADPOR_SET 0x00001000
-#define PM_RSTS_HADSRH_SET 0x00000400
-#define PM_RSTS_HADSRF_SET 0x00000200
-#define PM_RSTS_HADSRQ_SET 0x00000100
-#define PM_RSTS_HADWRH_SET 0x00000040
-#define PM_RSTS_HADWRF_SET 0x00000020
-#define PM_RSTS_HADWRQ_SET 0x00000010
-#define PM_RSTS_HADDRH_SET 0x00000004
-#define PM_RSTS_HADDRF_SET 0x00000002
-#define PM_RSTS_HADDRQ_SET 0x00000001
+#include <soc/bcm283x/wdt.h>
#define SECS_TO_WDOG_TICKS(x) ((x) << 16)
diff --git a/include/soc/bcm283x/wdt.h b/include/soc/bcm283x/wdt.h
new file mode 100644
index 000000000..ce97b1eb5
--- /dev/null
+++ b/include/soc/bcm283x/wdt.h
@@ -0,0 +1,40 @@
+/*
+ * Copyright (C) 2017 Pengutronix, Lucas Stach <l.stach at pengutronix.de>
+ *
+ * Based on code from Carlo Caione <carlo at carlocaione.org>
+ */
+
+#ifndef __BCM2835_WDT_H
+#define __BCM2835_WDT_H
+
+#define PM_RSTC 0x1c
+#define PM_RSTS 0x20
+#define PM_WDOG 0x24
+
+#define PM_WDOG_RESET 0000000000
+#define PM_PASSWORD 0x5a000000
+#define PM_WDOG_TIME_SET 0x000fffff
+#define PM_RSTC_WRCFG_CLR 0xffffffcf
+#define PM_RSTC_WRCFG_SET 0x00000030
+#define PM_RSTC_WRCFG_FULL_RESET 0x00000020
+#define PM_RSTC_RESET 0x00000102
+
+#define PM_RSTS_HADPOR_SET 0x00001000
+#define PM_RSTS_HADSRH_SET 0x00000400
+#define PM_RSTS_HADSRF_SET 0x00000200
+#define PM_RSTS_HADSRQ_SET 0x00000100
+#define PM_RSTS_HADWRH_SET 0x00000040
+#define PM_RSTS_HADWRF_SET 0x00000020
+#define PM_RSTS_HADWRQ_SET 0x00000010
+#define PM_RSTS_HADDRH_SET 0x00000004
+#define PM_RSTS_HADDRF_SET 0x00000002
+#define PM_RSTS_HADDRQ_SET 0x00000001
+
+#define PM_RSTS_HADDR_SET \
+ (PM_RSTS_HADDRQ_SET | PM_RSTS_HADDRF_SET | PM_RSTS_HADDRH_SET)
+#define PM_RSTS_HADWR_SET \
+ (PM_RSTS_HADWRQ_SET | PM_RSTS_HADWRF_SET | PM_RSTS_HADWRH_SET)
+#define PM_RSTS_HADSR_SET \
+ (PM_RSTS_HADSRQ_SET | PM_RSTS_HADSRF_SET | PM_RSTS_HADSRH_SET)
+
+#endif
--
2.17.1
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